Referring to a cylinder head of an engine, a product of complicated shapes including a cooling fin is integrally cast. Accordingly, it is not possible to release a die assembly only with a stationary die and a movable die and the movable die is provided with a plurality of slide cores. The prior art relating to these slide cores is disclosed in Patent Document 1 and the like.
Patent Document 1 discloses a slide die provided to approach and secede from a movable die from four (4) directions and, by holding the cores with these four slide dies, a surface contacting a cylinder block of the cylinder head while molten metal is poured is substantially in a vertical direction.
Patent Document 2 discloses that, in order to prevent the slide core from inclining when dies are clamped, the slide core is provided with a surface adapted to contact the movable die when set in the movable die, part of the slide core is formed to provide a protrusion, and this protrusion is received by the stationary die when the dies are clamped.
Patent reference 1: Japanese Unexamined Patent Publication No. 2000-33459
Patent reference 2: Japanese Unexamined Patent Publication No. 2007-111713